4.2.15. TwoBodyG file

This file determines the target components of the two-body Green’s function \(\langle c_{i\sigma_1}^{\dagger}c_{j\sigma_2}c_{k\sigma_3}^{\dagger}c_{l\sigma_4}\rangle\). For the spin system, the conditions \(i=j\) and \(k=l\) must be satisfied. An example of the file format is as follows.

=============================================
NCisAjsCktAltDC        576
=============================================
======== Green functions for Sq AND Nq ======
=============================================
    0     0     0     0     0     0     0     0
    0     0     0     0     0     1     0     1
    0     0     0     0     1     0     1     0
    0     0     0     0     1     1     1     1
    0     0     0     0     2     0     2     0
    0     0     0     0     2     1     2     1
    0     0     0     0     3     0     3     0
    0     0     0     0     3     1     3     1
    0     0     0     0     4     0     4     0
    0     0     0     0     4     1     4     1
    0     0     0     0     5     0     5     0
    0     0     0     0     5     1     5     1
    0     0     0     0     6     0     6     0
    0     0     0     0     6     1     6     1
    0     0     0     0     7     0     7     0
    0     0     0     0     7     1     7     1
    0     0     0     0     8     0     8     0
    0     0     0     0     8     1     8     1
    0     0     0     0     9     0     9     0
    0     0     0     0     9     1     9     1
    0     0     0     0    10     0    10     0
    0     0     0     0    10     1    10     1
    0     0     0     0    11     0    11     0
    0     0     0     0    11     1    11     1
    0     1     0     1     0     0     0     0
    ...

File format

• Line 1: Header
• Line 2: [string01] [int01]
• Lines 3-5: Header
• Lines 6-: [int02]  [int03]  [int04]  [int05]  [int06]  [int07]  [int08]  [int09].

Parameters

• [string01]

  Type : String (a blank parameter is not allowed)

  Description : A keyword for the total number of two-body Green’s functions. You can freely give a name to the keyword.

• [int01]

  Type : Int (a blank parameter is not allowed)

  Description : An integer giving the total number of two-body Green’s functions.

• [int02], [int04],[int06], [int08]

  Type : Int (a blank parameter is not allowed)

  Description : An integer giving a site index (\(0<=\) [int02], [int04], [int06], [int08] \(<\) Nsite).

• [int03], [int05],[int07], [int09]

  Type : Int (a blank parameter is not allowed)

  Description : An integer giving a spin index:

  For Hubbard or Kondo system, the index can be selected from

  0: Up-spin,

  1: Down-spin.

  For Spin system, the index can be selected from

  \(0, 1, \cdots, 2S+1\) (corresponding to -\(S-0.5, -S+0.5, \cdots S+0.5\)).

Use rules

• Headers cannot be omitted.
• A program is terminated when the components of the two-body Green’s functions are double counted.
• A program is terminated when the conditions \(i=j\) and \(k=l\) are not satisfied for the spin model.
• A program is terminated when [int01] is different from the total number of two-body Green’s functions defined in this file.
• A program is terminated, when [int02]-[int09] are outside the range of the defined values.